What’s Even the Point of Exit Interviews?

Even if you told them,they don't care how you were treated. They want to know what exactly drove you over the edge and what better environment and opportunity the competition offered you.

Exit interviews help future "stay" interviews. So when another person turns in their notice,they now have a list of things they can work with to try and keep them.

Also, they know you will avoid saying negative things if you're smart so they look for patterns of things people who leave are not saying under that specific managment compared to other teams.